/Engine/Plugins/Enterprise/DatasmithCADImporter/Source/CADInterfaces/Public/CADSceneGraph.h
An instance is link to its reference but It also save its tree of override occurrence children
class FArchiveInstance : public [CADLibrary::FArchiveWithOverridenChildren](API\Plugins\CADInterfaces\FArchiveWithOverridenChildren)
bool
bIsExternalReference
FCadId
ReferenceNodeId